Status Epilepticus

ACVIM Consensus Statement on the management of status epilepticus and cluster seizures in dogs and cats

BACKGROUND

Seizure emergencies (ie, status epilepticus [SE] and cluster seizures [CS]), are common challenging disorders with complex pathophysiology, rapidly progressive drug-resistant and self-sustaining character, and high morbidity and mortality. Current treatment approaches are characterized by considerable variations, but official guidelines are lacking.

OBJECTIVES

To establish evidence-based guidelines and an agreement among board-certified specialists for the appropriate management of SE and CS in dogs and cats.

ANIMALS

None.

MATERIALS AND METHODS

A panel of 5 specialists was formed to assess and summarize evidence in the peer-reviewed literature with the aim to establish consensus clinical recommendations. Evidence from veterinary pharmacokinetic studies, basic research, and human medicine also was used to support the panel's recommendations, especially for the interventions where veterinary clinical evidence was lacking.

RESULTS

The majority of the evidence was on the first-line management (ie, benzodiazepines and their various administration routes) in both species. Overall, there was less evidence available on the management of emergency seizure disorders in cats in contrast to dogs. Most recommendations made by the panel were supported by a combination of a moderate level of veterinary clinical evidence and pharmacokinetic data as well as studies in humans and basic research studies.

CONCLUSIONS AND CLINICAL RELEVANCE

Successful management of seizure emergencies should include an early, rapid, and stage-based treatment approach consisting of interventions with moderate to preferably high ACVIM recommendations; management of complications and underlying causes related to seizure emergencies should accompany antiseizure medications.

Refractory status epilepticus in children with and without prior epilepsy or status epilepticus

OBJECTIVE

To compare refractory convulsive status epilepticus (rSE) management and outcome in children with and without a prior diagnosis of epilepsy and with and without a history of status epilepticus (SE).

METHODS

This was a prospective observational descriptive study performed from June 2011 to May 2016 on pediatric patients (1 month-21 years of age) with rSE.

RESULTS

We enrolled 189 participants (53% male) with a median (25th-75th percentile) age of 4.2 (1.3-9.6) years. Eighty-nine (47%) patients had a prior diagnosis of epilepsy. Thirty-four (18%) patients had a history of SE. The time to the first benzodiazepine was similar in participants with and without a diagnosis of epilepsy (15 [5-60] vs 16.5 [5-42.75] minutes, p = 0.858). Patients with a diagnosis of epilepsy received their first non-benzodiazepine (BZD) antiepileptic drug (AED) later (93 [46-190] vs 50.5 [28-116] minutes, p = 0.002) and were less likely to receive at least one continuous infusion (35/89 [39.3%] vs 57/100 [57%], p = 0.03). Compared to patients with no history of SE, patients with a history of SE received their first BZD earlier (8 [3.5-22.3] vs 20 [5-60] minutes, p = 0.0073), although they had a similar time to first non-BZD AED (76.5 [45.3-124] vs 65 [32.5-156] minutes, p = 0.749). Differences were mostly driven by the patients with an out-of-hospital rSE onset.

CONCLUSIONS

Our study establishes that children with rSE do not receive more timely treatment if they have a prior diagnosis of epilepsy; however, a history of SE is associated with more timely administration of abortive medication.

Time from convulsive status epilepticus onset to anticonvulsant administration in children

OBJECTIVE

To describe the time elapsed from onset of pediatric convulsive status epilepticus (SE) to administration of antiepileptic drug (AED).

METHODS

This was a prospective observational cohort study performed from June 2011 to June 2013. Pediatric patients (1 month-21 years) with convulsive SE were enrolled. In order to study timing of AED administration during all stages of SE, we restricted our study population to patients who failed 2 or more AED classes or needed continuous infusions to terminate convulsive SE.

RESULTS

We enrolled 81 patients (44 male) with a median age of 3.6 years. The first, second, and third AED doses were administered at a median (p25-p75) time of 28 (6-67) minutes, 40 (20-85) minutes, and 59 (30-120) minutes after SE onset. Considering AED classes, the initial AED was a benzodiazepine in 78 (96.3%) patients and 2 (2-3) doses of benzodiazepines were administered before switching to nonbenzodiazepine AEDs. The first and second doses of nonbenzodiazepine AEDs were administered at 69 (40-120) minutes and 120 (75-296) minutes. In the 64 patients with out-of-hospital SE onset, 40 (62.5%) patients did not receive any AED before hospital arrival. In the hospital setting, the first and second in-hospital AED doses were given at 8 (5-15) minutes and 16 (10-40) minutes after SE onset (for patients with in-hospital SE onset) or after hospital arrival (for patients with out-of-hospital SE onset).

CONCLUSIONS

The time elapsed from SE onset to AED administration and escalation from one class of AED to another is delayed, both in the prehospital and in-hospital settings.

Management of status epilepticus in neurological versus medical intensive care unit: does it matter?

BACKGROUND

Admission of patients with status epilepticus (SE) to the neurosciences intensive care unit (NICU) may improve management and outcomes compared to general ICUs.

METHODS

We reviewed all patients with SE admitted to the NICU versus the Medical ICU in our institution between 2005 and 2008. We included only patients with definite or probable SE based on pre-defined criteria. We collected demographic and clinical data, including severity of admission scores and adjusted short-term outcomes for admission and management in the two ICUs.

RESULTS

There were 168 visits in 151 patients for definite or probable SE, 46 (27 %) of which were in the NICU and 122 (73 %) in the MICU. APACHE II scores were significant higher in the MICU group (17.5 vs 13.4, p = 0.003) and age in the NICU (58.3 vs 51.5 years, p = 0.041). More continuous EEGs were ordered in the NICU (85 vs 30 %, p < 0.001), where fewer patients were intubated, but more eventually tracheostomized. The NICU had a higher rate of complex partial SE and more alert or somnolent patients, whereas the MICU had a higher rate of generalized SE and more stuporous or comatose patients. Admission diagnoses also differed, with the NICU having higher rate of strokes and the MICU higher rate of toxometabolic etiologies (39 vs 12 % and 11 vs 21 %, p = 0.002). After adjustment, no difference was found in mortality, the ICU or hospital length of stay and modified Rankin score at discharge.

CONCLUSION

SE treatment revealed increased use of continuous EEG in NICU-admitted patients, but without concomitant reduction in LOS or discharge outcomes compared to the MICU.

Prolonged febrile seizures, clinical characteristics, and acute management

PURPOSE

Prolonged febrile seizures (PFS) lasting ≥15 min have been associated with increased risk for epilepsy in later life. Initial treatment, mostly prehospital, aims to prevent its evolution to febrile status epilepticus (FSE) and reduce adverse outcome. Paucity of information is available on the immediate treatment before reaching a hospital facility.

METHODS

We obtained data, prospectively, on all children who presented from January 2008 to March 2010 with PFS to the emergency rooms of four Israeli medical centers. Information related to seizure semiology, treatment, and medical history was collected into a predefined pro forma form and reviewed centrally.

KEY FINDINGS

Sixty children, median age 18.3 months (interquartile range [IQR] 12-28) were included with a median seizure duration of 35 min (IQR 26-60), 43 (71.7%) lasting ≥30 min. Seizures had focal onset in 34 infants (57%). Fifty-four families (90%) activated the ambulance service; median ambulance arrival time was 8 min (IQR 5-10), 33 (61%) were medically treated by the ambulance paramedic, of whom 15 (45%) responded to treatment. Twelve children with active seizures did not receive medications. Initial treatment with rectal diazepam was more common in those with seizure duration >30 min.

SIGNIFICANCE

Most children with PFS are treated with antiepileptic drugs early by the ambulance service. However, even timely treatment does not prevent status epilepticus in the majority of cases. These data highlight the need for effective early treatment of this common pediatric emergency.

Pharmacokinetics and tolerability of intranasal diazepam and midazolam in healthy adult volunteers

OBJECTIVE

The purpose of this pilot study was to determine the pharmacokinetics and tolerability of an investigational diazepam (DZP) formulation and a parenteral midazolam (MDZ) formulation following intranasal (i.n.) administration for the efficient treatment of seizure emergencies.

METHODS

Each subject received 5 mg of DZP and MDZ via both i.n. and intravenous routes in a four-way, randomized crossover trial. Blood samples were collected over 48 h. DZP and MDZ concentrations were measured using HPLC. Using analog scales, subjects rated tolerability (0 = no change from normal; 10 = maximum intolerability) and pain (0 = no pain; 4 = extreme pain) prior to and 0, 5, 15, 60 min, and 8 h after administration.

RESULTS

The C(max) and T(max) values for i.n. DZP and MDZ were 179.2 ng/ml and 28.8 min vs 62.8 ng/ml and 21.6 min, respectively. Immediately following i.n. administration, subjects reported tolerability scores of 6.75 and 6.0, and identical pain scores, 3.2, for DZP and MDZ, respectively.

CONCLUSION

Both formulations were rapidly absorbed following i.n. administration with transient discomfort. DZP had a longer half-life, which may result in an extended duration of action. Further studies in large patient populations to evaluate the safety after long term use, efficacy and pharmacokinetics of i.n. DZP are warranted.

Identification and treatment of acute repetitive seizures in children and adults

Acute repetitive seizures are a predictable component of a patient's seizure disorder, historically distinct from the patient's other epileptic seizures in type, frequency, severity, or duration, and with an onset easily recognized by caregiver and physician. Onset has a consistent predictable component (such as aura or prodrome, which may be a convulsive or nonconvulsive symptom, or characteristic single or multiple seizures) that is predictably and temporally linked to subsequent seizures. Typically there is recovery between seizures. Episodes may or may not progress to a prolonged seizure or to status epilepticus but may be predictable for each patient based on history. Acute repetitive seizures may include any type of epileptic seizure and may occur at any age. Other terms for acute repetitive seizures include cluster, serial, recurrent, or crescendo seizures. Treatment should only be administered by caregivers who in the opinion of the prescriber are capable of monitoring the clinical response and recognize when the response is such that immediate professional evaluation or care is necessary. Caregivers must be comfortable so that they feel capable of recognizing when and how to treat. The prescriber and caregiver should have a written plan on when to treat and what to observe and do after treatment. The most immediate treatment for out of hospital care and the only US Food and Drug Administration-approved product for acute repetitive seizures is rectal diazepam gel administered at a dose of 0.2 to 0.5 mg/kg, depending on age and weight (Class I evidence). Treatment may produce central nervous system depression. Oral, buccal, and sublingual benzodiazepines (lorazepam, diazepam) are also used for treatment but only if the risk of aspiration is not a concern and recognizing that absorption time will be increased (Class III evidence). Nasal benzodiazepine products, available in some countries, are not yet available in the United States.

Designing practical evidence-based treatment plans for children with prolonged seizures and status epilepticus

The adverse effects of prolonged seizures and status epilepticus can be reduced through appropriate, prompt, and aggressive intervention. Because most prolonged seizures and status epilepticus episodes begin outside the hospital, it is important to design treatment interventions that can be rendered at home or in school that do not rely entirely on intervention by emergency medical personnel. Factors that make this new approach possible include the use of evidence-based guidelines to inform treatment decisions and the successful development, and government approval, of new formulations of commonly used medications, including rectal diazepam gel and the phenytoin prodrug fosphenytoin. A useful plan should be initiated at the 5-minute to 10-minute mark (not the 30-minute mark) and contain clear, easy-to-read directions that can be implemented by family, school personnel, or emergency medical services who have varying levels of medical sophistication. Four scenarios illustrating these considerations are included and provide examples of plans that fulfill these criteria.

Determinants of outcomes after head cooling for neonatal encephalopathy

OBJECTIVE

The goal of this study was to evaluate the role of factors that may determine the efficacy of treatment with delayed head cooling and mild systemic hypothermia for neonatal encephalopathy.

METHODS

A total of 218 term infants with moderate to severe neonatal encephalopathy plus abnormal amplitude-integrated electroencephalographic recordings, assigned randomly to head cooling for 72 hours, starting within 6 hours after birth (with the rectal temperature maintained at 34.5 +/- 0.5 degrees C), or conventional care, were studied. Death or severe disability at 18 months of age was assessed in a multicenter, randomized, controlled study (the CoolCap trial).

RESULTS

Treatment, lower encephalopathy grade, lower birth weight, greater amplitude-integrated electroencephalographic amplitude, absence of seizures, and higher Apgar score, but not gender or gestational age, were associated significantly with better outcomes. In a multivariate analysis, each of the individually predictive factors except for Apgar score remained predictive. There was a significant interaction between treatment and birth weight, categorized as > or =25th or <25th percentile for term, such that larger infants showed a lower frequency of favorable outcomes in the control group but greater improvement with cooling. For larger infants, the number needed to treat was 3.8. Pyrexia (> or =38 degrees C) in control infants was associated with adverse outcomes. Although there was a small correlation with birth weight, the adverse effect of greater birth weight in control infants remained significant after adjustment for pyrexia and severity of encephalopathy.

CONCLUSIONS

Outcomes after hypothermic treatment were strongly influenced by the severity of neonatal encephalopathy. The protective effect of hypothermia was greater in larger infants.

Who is at risk for prolonged seizures?

This article reviews how long seizures last and how frequently seizures are prolonged, risk factors for prolonged seizures, and a conceptual framework that links them. These data are derived from studies of patients with a first unprovoked seizure, studies of children with febrile seizures, studies of population-based and community-based cohorts with newly diagnosed epilepsy and patients with refractory epilepsy, and treatment trials. Prolonged seizures that exceed 5 to 10 minutes are relatively common, and the key factor in the identification of those at risk is a history of a prior prolonged seizure. A subgroup of patients with seizures is predisposed to prolonged although not necessarily frequent seizures, which are associated with increased morbidity, increased emergency department visits, and a decreased quality of life. This article also addresses criteria used to justify treatment of a seizure once it has continued longer than 5 minutes and the rationale for such treatment.

Overview: definitions and classifications of seizure emergencies

Seizure emergencies are potentially life-threatening events that are under-recognized. Status epilepticus is associated with considerable rates of morbidity and mortality. Experts currently believe that any episode of seizure activity lasting 5 minutes or longer should be considered status epilepticus. Treatment should be initiated as early as possible; evidence has shown that once seizures persist for 5 to 10 minutes, they are unlikely to stop on their own in the subsequent few minutes. Prehospital treatment with benzodiazepines has been shown to reduce seizure activity significantly compared with seizures that remain untreated until the patient reaches the emergency department. The consequences of delayed treatment of status epilepticus include a serious risk of subsequent prolonged seizure activity or epileptogenesis, memory deficits, and learning difficulties. The importance of timely intervention in generalized tonic-clonic status epilepticus must be emphasized. Recent research has found that emergency department personnel fail to recognize the condition in children in 34% of cases.

Treatment of Status Epilepticus in Adults: Guidelines of the Italian League Against Epilepsy

Status epilepticus (SE) is a medical emergency which can lead to significant morbidity and mortality and requires prompt diagnosis and treatment. SE is differentiated into generalized or partial SE on the basis of its electro-clinical manifestations. The guidelines for the management of SE produced by the Italian League against Epilepsy also distinguish three different stages of SE (initial, established and refractory), based on time elapsed since the onset of the condition and responsiveness to previously administered drugs. Treatment should be started as soon as possible, particularly in generalized convulsive SE, and should include general support measures, drugs to suppress epileptic activity and, whenever possible, treatments aimed at relieving the underlying (causative) condition. Benzodiazepines are the first line antiepileptic agents, and i.v. lorazepam is generally preferred because it is associated with a lower risk of early relapses. If benzodiazepines fail to control seizures, i.v. phenytoin is usually indicated, though i.v. phenobarbital or i.v. valproate may also be considered. Refractory SE requires admission to an intensive care unit (ICU) to allow adequate monitoring and support of respiratory, metabolic and hemodynamic functions and cerebral electrical activity. In refractory SE, general anesthesia may be required. Propofol and thiopental represent first line agents in this setting, after careful assessment of potential risks and benefits.

Time to treatment in prolonged seizure episodes

Prompt intervention in seizure emergencies is critical to reducing morbidity and mortality risks associated with status epilepticus. To determine the need for wider education about the benefits of at-home treatment, we examined the time from seizure onset to initial treatment in a cohort of patients with epileptic seizures. The seizure database of patients admitted in the greater Richmond, Virginia, area during a 5-year period (1989-1994) was queried to extract time to seizure treatment. Records were available for 889 patients. Patients were divided into two subgroups: children (age < 16 years, 29.7% of the cohort) and adults. Time to seizure treatment varied broadly; only 41.5% of all patients received their first antiepilepsy drug within 30 minutes. Time to treatment did not significantly differ between age groups. This baseline study supports the need for patient education regarding seizure emergencies and wider availability of at-home treatment options to shorten time to seizure treatment.

New management strategies in the treatment of status epilepticus

Status epilepticus is a neurologic emergency associated with high mortality and long-term disability. Recent advances in our understanding of the pathophysiological mechanisms involved in the initiation and perpetuation of seizure activity have revealed that status epilepticus is a dynamic and evolving process. Alterations at the cellular level parallel physiological, physical, and electrical changes at the bedside. Loss of cerebral autoregulation and neuronal damage begin after 30 minutes of continuous seizure activity. This understanding has led to changes in treatments of status epilepticus, which must be multidisciplinary and occur simultaneously in many different areas. The goals of pharmacological therapy are to terminate seizures early and prevent recurrence. Two recent large clinical studies have shown the benefit of early administration of benzodiazepines to control status epilepticus. Pharmacological algorithms designed to focus medical management have trended toward earlier and more aggressive treatment. The hope is that continued exploration into the basic mechanisms involved in status epilepticus and future controlled clinical trials defining optimal medical management will produce further advances.

Status epilepticus: a review of different syndromes, their current evaluation, and treatment

BACKGROUND

Status epilepticus (SE) encompasses a wide range of seizure types with different clinical presentations, pathophysiologies, treatment imperatives, and outcomes. The most dramatic and life-threatening form, generalized convulsive status epilepticus, has been reviewed in all of these aspects, but other less common types of SE have been described less extensively.

REVIEW SUMMARY

Definitions of generalized convulsive SE and its pathophysiology are reviewed briefly. Defining SE by a specific duration of seizures is controversial and has implications for studies and for clinical management. Several types of SE are different in their causes, presentations, and outcomes. Many are underdiagnosed. This article focuses on the pharmacology and clinical studies of several anticonvulsant medications used to treat SE. A protocol approach is not detailed. Rather, the clinical evaluation begins with meticulous diagnosis of the type of SE. Establishing the SE syndrome diagnosis and use of anticonvulsants with demonstrated effectiveness facilitate an appropriate treatment plan for individual patients. Recent developments in the basic science of SE raise the possibility of better treatments in the future.

CONCLUSIONS

As there are many types of seizures, there are also many types of SE. Each has unique presentations and treatment considerations. Review of actual clinical data from SE treatment studies should be helpful in devising the best treatment for an individual patient.

Anticonvulsant and antiepileptogenic effects of fluorofelbamate in experimental status epilepticus

PURPOSE

To examine the seizure-protective properties of fluorofelbamate, a felbamate analog, on acute and chronic seizures in an experimental model of self-sustaining status epilepticus (SSSE).

METHODS

SSSE was induced by stimulation of the perforant path for 30 min (PPS) through chronically implanted electrodes in free-running adult male Wistar rats. Fluorofelbamate was injected intravenously (i.v.) either 10 min, or 40 min after SSSE induction. Seizure and spike profiles were analyzed off-line.

RESULTS

Fluorofelbamate injected during the early stages of SSSE (10 min after the end of PPS), shortened the duration of seizures in a dose-dependent manner. While a dose of 50 mg kg(-1) was ineffective, 100 and 200 mg kg(-1) reduced cumulative seizure time from 393 +/- 10 min to 15 +/- 8 min and 2.4 +/- 0.5 min respectively. Administration of fluorofelbamate (200 and 300 mg kg (-1)) at a late stage of SSSE, which is refractory to treatment with conventional anticonvulsants, also significantly attenuated seizures. Acute fluorofelbamate treatment (200 mg kg(-1) 10 min after PPS) significantly decreased the frequency of spontaneous seizures which follow SSSE after a 'latent' interval. Moreover, in contrast to control animals, fluorofelbamate-treated rats showed regression of spontaneous seizures, and an apparent remission of epilepsy within 2 months after SSSE.

CONCLUSIONS

Acute treatment of SSSE with fluorofelbamate showed strong anticonvulsant effects even during the late stages of SSSE. In this model, it also displayed antiepileptogenic properties: it reduced the severity of chronic epilepsy after SSSE and lead to apparent remissions of that epilepsy.

Progress in clinical neurosciences: Status epilepticus: a critical review of management options

Although generalized tonic-clonic status epilepticus (SE) is frequently seen, an evidence-based approach to management is limited by a lack of randomized clinical studies. Clinical practice, therefore, relies on a combination of expert recommendations, local hospital guidelines and dogma based on individual preference and past successes. This review explores selected and controversial aspects of SE in adults and provides a critical appraisal of currently recommended management strategies.

Use of propofol and other nonbenzodiazepine sedatives in the intensive care unit

Sedatives continue to be used on a routine basis in critically ill patients. Although many agents are available and some approach an ideal, none are perfect. Patients require continuous reassessment of their pain and need for sedation. Pathophysiologic abnormalities that cause agitation, confusion, or delirium must be identified and treated before unilateral administration of potent sedative agents that may mask potentially lethal insufficiencies. The routine use of standardized and validated sedation scales and monitors is needed. It is hoped that reliable objective monitors of patients' level of consciousness and comfort will be forthcoming. Each sedative agent discussed in this article seems to have a place in the ICU pharmacologic armamentarium to ensure the safe and comfortable delivery of care. Etomidate is an attractive agent for short-term use to provide the rapid onset and offset of sedation in critically ill patients who are at risk for hemodynamic instability but seem to need sedation or anesthesia to perform a procedure or manipulate the airway. Ketamine administered through intramuscular injection or intravenous infusion provides quick, intense analgesia and anesthesia and allows patients to tolerate limited but painful procedures. The risk/benefit ratio associated with the use of this neuroleptic agent must be weighed carefully. Ketamine is contraindicated in patients who lack normal intracranial compliance or who have significant myocardial ischemia. Barbiturates are reserved mainly to induce coma in patients at risk for severe CNS ischemia, which frequently is associated with refractory intracranial hypertension, or in patients with status epilepticus. When administered in high doses, these drugs have prolonged sedative and depressant effects. Judicious hemodynamic monitoring is required when barbiturate coma is induced. Haloperidol is indicated in the treatment of delirium. Patients should be monitored for extrapyramidal side effects and, when they require higher doses, for potential electrocardiographic prolongation of the QT interval. Dexmedetomidine may evolve into an agent with qualities comparable with midazolam and propofol, and it may even become a drug of choice in select patients. Further study is required, however. Propofol has many of the qualities of an ideal sedative agent. Benzodiazepines and narcotics often are used in concert with propofol to provide reliable amnesia and to relieve pain, respectively. Propofol frequently causes hypotension when administered as a bolus or infusion, particularly in patients with limited cardiac reserve or hypovolemia. More data must be obtained to identify potential deleterious effects of hypertriglyceridemia, and further evaluation of the potential benefits in certain patient populations, such as neurosurgical patients, is needed.

Treatment of status epilepticus

The approach to treatment of status epilepticus has changed because of the demonstration of decreased mortality with rapid intervention, completion of a randomized, double-blind VA Cooperative study comparing first-line agents, and further understanding of the pathophysiologic changes discovered in experimental animal studies. This article reviews the treatments of generalized convulsive status epilepticus in the prehospital, emergency department, and intensive care unit settings.

[Antiepileptic treatment in cerebral lesions: what are the indications and the main practical use?]

The aim of this report is to review the indication and the practical use of the antiepileptic drugs in patients with cerebral lesions. The use of antiepileptic drugs to treat seizure or status epilepticus in an emergency is well catalogued and reported in this paper. Practical use of antiepileptic drugs, after a first seizure or to prevent a seizure, in patients with a cerebral lesion, is controversial. The question of antiepileptic drugs in seizures and in prophylaxis is discussed in different types of cerebral lesions: head injury, stroke, cerebral arteriovenous malformation and cerebral tumour.

Neuroprotective effects of early vs. late administration of dantrolene in experimental status epilepticus

We examined the effects of dantrolene, an inhibitor of intracellular calcium release, on hippocampal neuronal damage associated with 140 min of limbic status epilepticus in the rat. Dantrolene (10 mg/kg i.p.) was administered after either 30 min or 140 min of status epilepticus. Early administration was associated with a significant reduction in the amount of neuronal injury in all hippocampal subregions, while late administration was associated with less neuronal injury in area CA3 only. These findings suggest that a substantial portion of seizure-induced hippocampal injury is associated with release of calcium from intracellular stores, and that early administration of dantrolene may be a useful adjunct to anticonvulsant treatment of status epilepticus.

Topiramate reduces neuronal injury after experimental status epilepticus

Prolonged seizures are associated with injury to vulnerable neurons, particularly in the hippocampus. Identification of compounds that attenuate injury after prolonged seizures could be of value in the management of refractory status epilepticus. We hypothesized that topiramate, an anticonvulsant with multiple mechanisms of action, would attenuate hippocampal neuronal injury when given after experimental status epilepticus. Limbic status epilepticus was induced in adult male Wistar rats for 140 min by unilateral hippocampal electrical stimulation. Rats then received intraperitoneal injections of either vehicle (n=6) or topiramate at 20 mg/kg (n=6), 40 mg/kg (n=7) or 80 mg/kg (n=7). Three days later, hippocampal sections were processed for neuronal degeneration using a silver impregnation stain. Seizure-induced damage was assessed by measuring the density of silver staining in hippocampal regions CA1, CA3 and dentate hilus. Administration of topiramate at each dose was associated with a significant reduction in staining density bilaterally in area CA1 and the dentate hilus. Reduction in staining density in area CA3 was seen contralateral to the side of stimulation at the two higher topiramate doses only. The results indicate that administration of topiramate after experimental status epilepticus can attenuate seizure-induced hippocampal neuronal injury.

Evaluation of the patient with seizures: an evidence based approach

Statistics tell us that as many as 1 in 20 members of the population will suffer a seizure at some point in their lifetime, a figure which becomes even more likely if one lives to the age of 80. Thus, a careful evidence based approach to the patient with seizure is immensely useful to the emergency physician. The authors evaluate current studies on the subject, discuss seizures as they relate to specific patient groups, and, ultimately, make recommendations on this important subject.

Continuous EEG monitoring in the neuroscience intensive care unit and emergency department

This article reviews established, emergent, and potential applications of continuous EEG (CEEG) monitoring in the Neuroscience Intensive Care Unit (NICU) and Emergency Department. In each application, its goal as a neurophysiologic monitor is to extend our powers of observation to detect abnormalities at a reversible stage and to guide timely and physiologically sound interventions. Since this subject was reviewed 5 years ago, the use of CEEG monitoring has become more widespread. In a modern NICU, it is no longer novel to have CEEG data contributing to management decisions. A well-trained CEEG monitoring team is important for its optimal implementation. In the diagnosis and management of convulsive and nonconvulsive status epilepticus, its value appears established. It is finding benefit in the early diagnosis and management of precarious cerebral ischemia, including severe acute cerebral infarctions and post-SAH vasospasms. In comatose patients, it can provide diagnostic and prognostic information which is otherwise unobtainable. More recently, it has been found advantageous for targeting management of acute severe head trauma patients. Networking technology has facilitated the implementation and oversight of CEEG monitoring and promises to expand its availability, credibility, and effectiveness. The maturing of CEEG use is reflected in preliminary efforts to assess its cost benefit, cost effectiveness, and impact on patient outcomes.

Management of status epilepticus

The pharmacologic management of major motor status epilepticus is summarized. When general anesthesia is required, the electroencephalogram (EEG) is used for monitoring the adequacy of treatment. The EEG findings may also be important in recognizing status epilepticus and monitoring its response to treatment when this is clinically difficult, as when it occurs in comatose or pharmacologically paralyzed patients or in the context of severe brain damage. Finally, the EEG helps to clarify the nature of motor activities of uncertain basis in patients in the intensive care unit and has indicated that non-convulsive seizures or status are more common than clinically suspected in such patients.

[Status epilepticus: indications for emergency EEG]

EEG is a major tool in convulsive status epilepticus. Several techniques may be used, including conventional or digitized EEG using 4, 8, 10 or 16 channels, continuous monitoring with or without simultaneous video recording, and cerebral function monitor. During the first phase, in the emergency ward, EEG may be useful in severe convulsive status epilepticus to assess further evolution and/or prognosis. However, rapid control of seizure at this phase is the primary goal, and optimization of EEG availabilities may lead to more systematic indications. After adequate control of seizures, EEG is mandatory in the following situations: i) a difficult-to-control convulsive status epilepticus, with a high risk of subsequent evolution towards subtle status epilepticus; ii) a resistant status epilepticus which needed high dose of sedatives drugs and/or curarization, to evaluate the level of anaesthesia and to watch for recurrence of epileptiform abnormalities; iii) a permanent, unexplained impairment of consciousness which followed an apparently successful treatment, to detect non convulsive status epilepticus; 4. a doubtful clinical diagnosis, to confirm pseudo-status epilepticus.